Asus E3746 - Manual (Page 41)

ROG Striker II Extreme / Striker II NSE 2-15
5. Rotate each fastener clockwise to
ensure correct orientation when
reinstalling.
Narrow end of the groove
Refer to the documentation in the boxed or stand-alone CPU fan package for
detailed information on CPU fan installation.
The narrow end of the
groove should point outward
after resetting. (The photo
shows the groove shaded for
emphasis.)